1. Field of the Invention
The invention relates to dog foods and to methods of preparing such.
2. Prior Art
Canadian Pat. No. 560,490 discloses a process for obtaining a pet food having a pH of about 2.0 to 5.0. The pH of a pet food is adjusted to a pH of about 2.0 to 5.0. The pet food is then heated to between about 140.degree. to 200.degree. F. (usually for about 15 minutes) and stuffed into a container (for example a plastic bag), which is cooled after being sealed. The pre-cooked pet food contains proteinaceous meaty materials. The specification (col. 3) states that the moisture content can vary widely, as desired, but the lowest water range given is 30 to 40 percent. Examples of the pH adjusters are citric acid and acid salts.
U.S. Pat. No. 3,115,409 (Hallinan et al.) corresponds to Canadian Pat. No. 560,490.
U.S. Pat. No. 3,202,514 (Burgess et al.) discloses a deformable, moist, shape-retaining, meat-based animal food having a pH of 6.0 to 8.0. The moisture level is 15 to 35 percent. The animal food can contain an antimycotic agent such as sorbic acid. The broad disclosure in the specification of Burgess et al, is not limited to a pH of 6.0 to 8.0, but all of its claims are. Burgess et al, clearly asserts that a product with a high acid value is unpalatable.
Burgess et al. states:
"Moreover, if one deviates from the critical conditions disclosed in Hallinan et al., viz., `hot` packaging and adjustment of product pH to an acid range, microbiological decomposition and spoilage is encountered on a scale which, heretofore, rendered such a product unfit for animal consumption." PA0 "In addition, the acid values of Hallinan et al.'s composition will hydrolyze the sugars and proteins present giving rise to unsightly darkening as well as off odors in the product. Importantly, moreover, a product of a high acid value detracts from palatability. Yet animal food formulators and processors apparently have believed that in order to stabilize a product of more than about 10% moisture without commercial sterilization or freezing, pH adjustment to less than 4.5 as well as `hot` packaging was necessary." [col. 2, lines 53 to 68]
U.S. Pat. No. 3,862,336 (Kofsky et al.) seeks to provide an intermediate moisture animal food which, after packaging in moisture-proof wrapping material, could be stored in non-refrigerated conditions without the risk of microbiological spoilage. The plasticity and viscosity of its product is stated to be controllable by the nature and quantity of the gelling and binding agents. The animal food composition of Kofsky et al. is substantially neutral. The disclosure of Kofsky et al. regarding ingredients and amounts thereof shows that Kofsky et al. is very similar to Burgess et al. The main areas where Kofsky et al. differs from Burgess et al. is the absence of cooking/pasteurization treatment and the addition of a water-soluble gum or gelatin.
The microbiologically stable, substantially neutral, nutritionally balanced, semi-plastic non-pasteurized, uncooked animal food composition of Kofsky et al, consists essentially of (1) a dried proteinaceous food substance, (2) an aqueous matrix including a water soluble colloidal binding and gelling agent (i.e., gelatin or water soluble gum), and (3) a water soluble, low molecular weight solid, liquid or mixture thereof in an amount sufficient to increase the osmotic pressure of the water in which it is dissolved thereby providing a bacteriostatic effect. The moisture content of the food composition ranges from about 15 percent to not greater than 25 percent. The amount of the gum or gelatin ranges from about 1/2 to about 10 percent by weight. The process for preparing the animal food composition involves blending a premix of the solids with a proportional amount of a pre-mix of the liquid with high-speed agitation.
Citric acid is used in the dog biscuits marketed by Nabisco, Inc., under the registered trademark "MILK BONE". Dogs like the flavor provided by the citric acid.
Acidulants are used in processed food products as an aid in sterilization. Sterilization of canned food products, in particular, depends on the thermal kill efficiency of the heat applied in retorts and other processing equipment. Many bacteria are highly resistant to heat and in some instances revert to a spore form which can survive high temperatures for a long period of time. Incomplete sterilization can result in instances of botulism or food spoilage. Bacteria and other deleterious microorganisms are more susceptible to thermal kill in a low pH environment. So acidification to lower the pH to a safe level is often used. Many food products, which formerly could not have been adequately sterilized, are now safely processed and maintained for long periods of time through the technique of acidification. Johnson, Arnold H., et al., "Encyclopedia of Food Technology", The Avis Publishing Company, Inc., (1974), p. 1.
Star-Kist Foods, Inc. markets "Smoky Link" dog snacks. The label contains the copyright date of 1987. The label listed ingredients are ground wheat, water, beef, soybean meal, propylene glycol (a preservative), pregelatinized wheat flour, animal fat preserved with BHA, dried whole egg, natural smoke flavoring, salt, phosphoric acid, milk protein hydrolysate, potassium sorbate (a preservative), choline chloride, papain, artificial colors, Vitamin E supplement, Vitamin A supplement, niacin, calcium pantothenate, riboflavin, Vitamin D.sub.3 supplement, Vitamin B.sub.12 supplement, pyridoxine hydrochloride, thiamine, mononitrate, and folic acid.